The production of batteries is becoming more and more automated, and as a result it has become increasingly desirable to have more of the assembly work undertaken automatically by machine. In the past many of the processing steps were hand operations as placement of elements and covers sometimes required some hand fitting. As materials have developed in the last few years, it has been possible to continuously decrease the sidewall thickness of battery jars to reduce costs and weight. However, I have found that as the sidewalls of battery jars become increasingly thinner, there is a greater likelihood that the jar's sidewalls will bow inwardly and this problem becomes more compounded as the size of the battery jar increases. Thus, the problems of automating battery production would seem to be further compounded.
Attention is directed to my co-pending application, U.S. patent application No. 087,149 now U.S. Pat. No. 4,276,360, directed to An Improved Battery Jar Cover. One of the significant features of that cover is the provision of a guide device positioned inwardly from the edges which can, for example, take the form of a plurality of legs which extend around the periphery of the cover. These legs help assure the correct shaping of the battery jar sidewalls as the cover is inserted and the formation of accurate and strong welded joints. To ease insertion into the jar each leg has a sloped bottom surface which aids in that insertion.
While I have found that these sloped bottom surfaces on the legs forming the guiding device make this cover relatively easily insertable if the sidewalls of a battery jar are bowed the cover might not be correctly insertable by machine. However, I have found that when automating the cover welding process, by altering the shape of this guide device, I can obtain a type of camming action as the guide is inserted into the battery jar which incrementally pushes the bowed sidewalls out thereby correcting any wall bowing situations. This action can be obtained if the length of the guide device, extending along each side from the corner to the center, varies in length with the guide device at the corners being longer than that portion appearing at or near the center. As battery covers with this modified guide configuration are inserted into the battery jar, the sidewalls are automatically moved outwardly so that none of the legs become engaged on the exterior of the jar's sidewalls and the covers are easily insertable automatically by machine.
This construction produces greater assurance that cover placement will occur correctly and enhances the ability to place covers on jars automatically by machinery prior to welding.